From eb7b665536c04fdc071530b7d00f80de29ef9723 Mon Sep 17 00:00:00 2001
From: Steven Hugg <hugg@fasterlight.com>
Date: Thu, 20 Aug 2020 11:41:58 -0500
Subject: [PATCH] if error line position is available, underline

---
 css/ui.css                   |  3 +++
 src/common/basic/compiler.ts |  3 ++-
 src/ide/views.ts             | 30 +++++++++++++++++++++---------
 3 files changed, 26 insertions(+), 10 deletions(-)

diff --git a/css/ui.css b/css/ui.css
index 3012b5d0..396b60d5 100644
--- a/css/ui.css
+++ b/css/ui.css
@@ -28,6 +28,9 @@
 .currentpc-marker-blocked {
   color: #ffee33;
 }
+.mark-error {
+  text-decoration: underline wavy 1px #ff6666;
+}
 .tooltipbox {
     position: relative;
     display: inline-block;
diff --git a/src/common/basic/compiler.ts b/src/common/basic/compiler.ts
index 362ac39f..b1c95b37 100644
--- a/src/common/basic/compiler.ts
+++ b/src/common/basic/compiler.ts
@@ -353,7 +353,8 @@ export class BASICParser {
         this.scopestack = [];
     }
     addError(msg: string, loc?: SourceLocation) {
-        if (!loc) loc = this.peekToken().$loc;
+        var tok = this.lasttoken || this.peekToken();
+        if (!loc) loc = tok.$loc;
         this.errors.push({path:loc.path, line:loc.line, label:this.curlabel, start:loc.start, end:loc.end, msg:msg});
     }
     compileError(msg: string, loc?: SourceLocation) {
diff --git a/src/ide/views.ts b/src/ide/views.ts
index 1b2a38ec..7ff7c52d 100644
--- a/src/ide/views.ts
+++ b/src/ide/views.ts
@@ -92,6 +92,7 @@ export class SourceEditor implements ProjectView {
   markCurrentPC; // TextMarker
   errormsgs = [];
   errorwidgets = [];
+  errormarks = [];
   inspectWidget;
 
   createDiv(parent:HTMLElement) {
@@ -210,6 +211,23 @@ export class SourceEditor implements ProjectView {
 
   getPath() : string { return this.path; }
 
+  addError(info: WorkerError) {
+    // only mark errors with this filename, or without any filename
+    if (!info.path || this.path.endsWith(info.path)) {
+      var numLines = this.editor.lineCount();
+      var line = info.line-1;
+      if (line < 0 || line >= numLines) line = 0;
+      this.addErrorMarker(line, info.msg);
+      if (info.start != null) {
+        var markOpts = {className:"mark-error", inclusiveLeft:true};
+        var start = {line:line, ch:info.end?info.start:info.start-1};
+        var end = {line:line, ch:info.end?info.end:info.start};
+        var mark = this.editor.markText(start, end, markOpts);
+        this.errormarks.push(mark);
+      }
+    }
+  }
+
   addErrorMarker(line:number, msg:string) {
     var div = document.createElement("div");
     div.setAttribute("class", "tooltipbox tooltiperror");
@@ -237,15 +255,9 @@ export class SourceEditor implements ProjectView {
   markErrors(errors:WorkerError[]) {
     // TODO: move cursor to error line if offscreen?
     this.clearErrors();
-    var numLines = this.editor.lineCount();
     errors = errors.slice(0, MAX_ERRORS);
     for (var info of errors) {
-      // only mark errors with this filename, or without any filename
-      if (!info.path || this.path.endsWith(info.path)) {
-        var line = info.line-1;
-        if (line < 0 || line >= numLines) line = 0;
-        this.addErrorMarker(line, info.msg);
-      }
+      this.addError(info);
     }
   }
 
@@ -255,8 +267,8 @@ export class SourceEditor implements ProjectView {
     this.dirtylisting = true;
     // clear line widgets
     this.errormsgs = [];
-    while (this.errorwidgets.length)
-      this.errorwidgets.shift().clear();
+    while (this.errorwidgets.length) this.errorwidgets.shift().clear();
+    while (this.errormarks.length) this.errormarks.shift().clear();
   }
 
   getSourceFile() : SourceFile { return this.sourcefile; }